Topical oral medication for the prevention of dental caries has been the subject of scientific investigation since about 1940. With the advent of topical fluorides, the interest in the use of dentifrices for the prevention of dental caries has increased. Studies involving dentifrices containing approximately 0.76% sodium monofluorophosphate, Na.sub.2 PFO.sub.3, as the active ingredient (e.g. Colgate.RTM. with MFP and Macleans Fluoride.RTM.) has established that dentifrices can be effective in helping to prevent caries (Accepted Dental Therapeutics, 37th ed., 1977, pp. 302-304). Similar studies for dentifrices containing about 0.4% stannous fluoride (SnF.sub.2), e.g. Crest.RTM. and Aim.RTM., have produced results in the same general range.
Sodium fluoride is also known to be effective for the prevention of dental caries but not to the same degree of effectiveness as sodium monofluorophosphate or stannous fluoride. The present invention unexpectedly reveals that sodium fluoride when use in a gel composition and in combination with an antibacterial agent prevents or treats caries of tooth roots significantly better than gels containing sodium monofluorophosphate or stannous fluoride.